A so-called “radial magnetic bearing” controls the radial position of the rotating shaft with magnetic force. Among various kinds of such magnetic bearings, a one in which a magnetic circuit is arranged within a plane that intersects at right angles with the rotating shaft is generally called a “heteropolar magnetic bearing”. In some heteropolar magnetic bearings, a pair of magnetic poles, for example, may form one independent magnetic circuit to support the rotating shaft (see, for example, Patent Document 1). Since the supporting force generated by the magnetic bearing depends on the cross-sectional area of teeth located closer to the inner periphery of a stator core, those teeth suitably have a broad width.